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12#include <linux/f2fs_fs.h>
13#include "f2fs.h"
14#include "xattr.h"
15#include "acl.h"
16
17static inline size_t f2fs_acl_size(int count)
18{
19 if (count <= 4) {
20 return sizeof(struct f2fs_acl_header) +
21 count * sizeof(struct f2fs_acl_entry_short);
22 } else {
23 return sizeof(struct f2fs_acl_header) +
24 4 * sizeof(struct f2fs_acl_entry_short) +
25 (count - 4) * sizeof(struct f2fs_acl_entry);
26 }
27}
28
29static inline int f2fs_acl_count(size_t size)
30{
31 ssize_t s;
32
33 size -= sizeof(struct f2fs_acl_header);
34 s = size - 4 * sizeof(struct f2fs_acl_entry_short);
35 if (s < 0) {
36 if (size % sizeof(struct f2fs_acl_entry_short))
37 return -1;
38 return size / sizeof(struct f2fs_acl_entry_short);
39 } else {
40 if (s % sizeof(struct f2fs_acl_entry))
41 return -1;
42 return s / sizeof(struct f2fs_acl_entry) + 4;
43 }
44}
45
46static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
47{
48 int i, count;
49 struct posix_acl *acl;
50 struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
51 struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
52 const char *end = value + size;
53
54 if (size < sizeof(struct f2fs_acl_header))
55 return ERR_PTR(-EINVAL);
56
57 if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
58 return ERR_PTR(-EINVAL);
59
60 count = f2fs_acl_count(size);
61 if (count < 0)
62 return ERR_PTR(-EINVAL);
63 if (count == 0)
64 return NULL;
65
66 acl = posix_acl_alloc(count, GFP_NOFS);
67 if (!acl)
68 return ERR_PTR(-ENOMEM);
69
70 for (i = 0; i < count; i++) {
71
72 if ((char *)entry > end)
73 goto fail;
74
75 acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag);
76 acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
77
78 switch (acl->a_entries[i].e_tag) {
79 case ACL_USER_OBJ:
80 case ACL_GROUP_OBJ:
81 case ACL_MASK:
82 case ACL_OTHER:
83 entry = (struct f2fs_acl_entry *)((char *)entry +
84 sizeof(struct f2fs_acl_entry_short));
85 break;
86
87 case ACL_USER:
88 acl->a_entries[i].e_uid =
89 make_kuid(&init_user_ns,
90 le32_to_cpu(entry->e_id));
91 entry = (struct f2fs_acl_entry *)((char *)entry +
92 sizeof(struct f2fs_acl_entry));
93 break;
94 case ACL_GROUP:
95 acl->a_entries[i].e_gid =
96 make_kgid(&init_user_ns,
97 le32_to_cpu(entry->e_id));
98 entry = (struct f2fs_acl_entry *)((char *)entry +
99 sizeof(struct f2fs_acl_entry));
100 break;
101 default:
102 goto fail;
103 }
104 }
105 if ((char *)entry != end)
106 goto fail;
107 return acl;
108fail:
109 posix_acl_release(acl);
110 return ERR_PTR(-EINVAL);
111}
112
113static void *f2fs_acl_to_disk(struct f2fs_sb_info *sbi,
114 const struct posix_acl *acl, size_t *size)
115{
116 struct f2fs_acl_header *f2fs_acl;
117 struct f2fs_acl_entry *entry;
118 int i;
119
120 f2fs_acl = f2fs_kmalloc(sbi, sizeof(struct f2fs_acl_header) +
121 acl->a_count * sizeof(struct f2fs_acl_entry),
122 GFP_NOFS);
123 if (!f2fs_acl)
124 return ERR_PTR(-ENOMEM);
125
126 f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
127 entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
128
129 for (i = 0; i < acl->a_count; i++) {
130
131 entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag);
132 entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
133
134 switch (acl->a_entries[i].e_tag) {
135 case ACL_USER:
136 entry->e_id = cpu_to_le32(
137 from_kuid(&init_user_ns,
138 acl->a_entries[i].e_uid));
139 entry = (struct f2fs_acl_entry *)((char *)entry +
140 sizeof(struct f2fs_acl_entry));
141 break;
142 case ACL_GROUP:
143 entry->e_id = cpu_to_le32(
144 from_kgid(&init_user_ns,
145 acl->a_entries[i].e_gid));
146 entry = (struct f2fs_acl_entry *)((char *)entry +
147 sizeof(struct f2fs_acl_entry));
148 break;
149 case ACL_USER_OBJ:
150 case ACL_GROUP_OBJ:
151 case ACL_MASK:
152 case ACL_OTHER:
153 entry = (struct f2fs_acl_entry *)((char *)entry +
154 sizeof(struct f2fs_acl_entry_short));
155 break;
156 default:
157 goto fail;
158 }
159 }
160 *size = f2fs_acl_size(acl->a_count);
161 return (void *)f2fs_acl;
162
163fail:
164 kfree(f2fs_acl);
165 return ERR_PTR(-EINVAL);
166}
167
168static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type,
169 struct page *dpage)
170{
171 int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
172 void *value = NULL;
173 struct posix_acl *acl;
174 int retval;
175
176 if (type == ACL_TYPE_ACCESS)
177 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
178
179 retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage);
180 if (retval > 0) {
181 value = f2fs_kmalloc(F2FS_I_SB(inode), retval, GFP_F2FS_ZERO);
182 if (!value)
183 return ERR_PTR(-ENOMEM);
184 retval = f2fs_getxattr(inode, name_index, "", value,
185 retval, dpage);
186 }
187
188 if (retval > 0)
189 acl = f2fs_acl_from_disk(value, retval);
190 else if (retval == -ENODATA)
191 acl = NULL;
192 else
193 acl = ERR_PTR(retval);
194 kfree(value);
195
196 return acl;
197}
198
199struct posix_acl *f2fs_get_acl(struct inode *inode, int type, bool rcu)
200{
201 if (rcu)
202 return ERR_PTR(-ECHILD);
203
204 return __f2fs_get_acl(inode, type, NULL);
205}
206
207static int f2fs_acl_update_mode(struct inode *inode, umode_t *mode_p,
208 struct posix_acl **acl)
209{
210 umode_t mode = inode->i_mode;
211 int error;
212
213 if (is_inode_flag_set(inode, FI_ACL_MODE))
214 mode = F2FS_I(inode)->i_acl_mode;
215
216 error = posix_acl_equiv_mode(*acl, &mode);
217 if (error < 0)
218 return error;
219 if (error == 0)
220 *acl = NULL;
221 if (!in_group_p(i_gid_into_mnt(&init_user_ns, inode)) &&
222 !capable_wrt_inode_uidgid(&init_user_ns, inode, CAP_FSETID))
223 mode &= ~S_ISGID;
224 *mode_p = mode;
225 return 0;
226}
227
228static int __f2fs_set_acl(struct inode *inode, int type,
229 struct posix_acl *acl, struct page *ipage)
230{
231 int name_index;
232 void *value = NULL;
233 size_t size = 0;
234 int error;
235 umode_t mode = inode->i_mode;
236
237 switch (type) {
238 case ACL_TYPE_ACCESS:
239 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
240 if (acl && !ipage) {
241 error = f2fs_acl_update_mode(inode, &mode, &acl);
242 if (error)
243 return error;
244 set_acl_inode(inode, mode);
245 }
246 break;
247
248 case ACL_TYPE_DEFAULT:
249 name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
250 if (!S_ISDIR(inode->i_mode))
251 return acl ? -EACCES : 0;
252 break;
253
254 default:
255 return -EINVAL;
256 }
257
258 if (acl) {
259 value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size);
260 if (IS_ERR(value)) {
261 clear_inode_flag(inode, FI_ACL_MODE);
262 return PTR_ERR(value);
263 }
264 }
265
266 error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0);
267
268 kfree(value);
269 if (!error)
270 set_cached_acl(inode, type, acl);
271
272 clear_inode_flag(inode, FI_ACL_MODE);
273 return error;
274}
275
276int f2fs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
277 struct posix_acl *acl, int type)
278{
279 if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
280 return -EIO;
281
282 return __f2fs_set_acl(inode, type, acl, NULL);
283}
284
285
286
287
288
289static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl,
290 gfp_t flags)
291{
292 struct posix_acl *clone = NULL;
293
294 if (acl) {
295 int size = sizeof(struct posix_acl) + acl->a_count *
296 sizeof(struct posix_acl_entry);
297 clone = kmemdup(acl, size, flags);
298 if (clone)
299 refcount_set(&clone->a_refcount, 1);
300 }
301 return clone;
302}
303
304static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
305{
306 struct posix_acl_entry *pa, *pe;
307 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
308 umode_t mode = *mode_p;
309 int not_equiv = 0;
310
311
312
313 FOREACH_ACL_ENTRY(pa, acl, pe) {
314 switch (pa->e_tag) {
315 case ACL_USER_OBJ:
316 pa->e_perm &= (mode >> 6) | ~S_IRWXO;
317 mode &= (pa->e_perm << 6) | ~S_IRWXU;
318 break;
319
320 case ACL_USER:
321 case ACL_GROUP:
322 not_equiv = 1;
323 break;
324
325 case ACL_GROUP_OBJ:
326 group_obj = pa;
327 break;
328
329 case ACL_OTHER:
330 pa->e_perm &= mode | ~S_IRWXO;
331 mode &= pa->e_perm | ~S_IRWXO;
332 break;
333
334 case ACL_MASK:
335 mask_obj = pa;
336 not_equiv = 1;
337 break;
338
339 default:
340 return -EIO;
341 }
342 }
343
344 if (mask_obj) {
345 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
346 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
347 } else {
348 if (!group_obj)
349 return -EIO;
350 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
351 mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
352 }
353
354 *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
355 return not_equiv;
356}
357
358static int f2fs_acl_create(struct inode *dir, umode_t *mode,
359 struct posix_acl **default_acl, struct posix_acl **acl,
360 struct page *dpage)
361{
362 struct posix_acl *p;
363 struct posix_acl *clone;
364 int ret;
365
366 *acl = NULL;
367 *default_acl = NULL;
368
369 if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
370 return 0;
371
372 p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage);
373 if (!p || p == ERR_PTR(-EOPNOTSUPP)) {
374 *mode &= ~current_umask();
375 return 0;
376 }
377 if (IS_ERR(p))
378 return PTR_ERR(p);
379
380 clone = f2fs_acl_clone(p, GFP_NOFS);
381 if (!clone) {
382 ret = -ENOMEM;
383 goto release_acl;
384 }
385
386 ret = f2fs_acl_create_masq(clone, mode);
387 if (ret < 0)
388 goto release_clone;
389
390 if (ret == 0)
391 posix_acl_release(clone);
392 else
393 *acl = clone;
394
395 if (!S_ISDIR(*mode))
396 posix_acl_release(p);
397 else
398 *default_acl = p;
399
400 return 0;
401
402release_clone:
403 posix_acl_release(clone);
404release_acl:
405 posix_acl_release(p);
406 return ret;
407}
408
409int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage,
410 struct page *dpage)
411{
412 struct posix_acl *default_acl = NULL, *acl = NULL;
413 int error;
414
415 error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage);
416 if (error)
417 return error;
418
419 f2fs_mark_inode_dirty_sync(inode, true);
420
421 if (default_acl) {
422 error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl,
423 ipage);
424 posix_acl_release(default_acl);
425 } else {
426 inode->i_default_acl = NULL;
427 }
428 if (acl) {
429 if (!error)
430 error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl,
431 ipage);
432 posix_acl_release(acl);
433 } else {
434 inode->i_acl = NULL;
435 }
436
437 return error;
438}
439
